Is there a definition of "consistent units" offered by the book or instructor?

Yes,yes! Sorry I wasn't able to define.

This is what is EXACTLY written :)

Unit Consistency

whenever you make calculations involving measurements, always remember to check for unit consistency; that is, the units should belong in the same system. Generally, if you are using meter for length, you should use gram for mass. Within the SI, the system of units based on the use of meter and kilogram is referred to as the MKS (meter-kilogram-second) system. Another system is the CGS system, which uses the centimeter, gram and second.

I think they mean which are dimensionally the same.
The basic dimensions are length, mass, time (plus temperature, and current)

So for example speed is length/time so could be given in miles/hour, m/s, km/min furlong/fortnight etc but could never be km/kg
So two sets of units are consistent if they refer to the set of same base units.

Staff: Mentor

whenever you make calculations involving measurements, always remember to check for unit consistency; that is, the units should belong in the same system. Generally, if you are using meter for length, you should use gram for mass. Within the SI, the system of units based on the use of meter and kilogram is referred to as the MKS (meter-kilogram-second) system. Another system is the CGS system, which uses the centimeter, gram and second.

I didn't get it. It's confusing me :(

Oh, I understand now. Well, except for the typo in the sentence that says "if you are using meter for length, you should use gram for mass." That is incorrect. As the rest of the paragraph states, the typical unit systems are:

MKS (SI) -- meter, kilogram, second

cgs -- centimeter, gram, second

There are similar consistent unit systems for goofy units like we use here in the US (pounds, whatever). This is a pretty good intro to units, with pointers out to other articles:

I think they mean which are dimensionally the same.
The basic dimensions are length, mass, time (plus temperature, and current)

So for example speed is length/time so could be given in miles/hour, m/s, km/min furlong/fortnight etc but could never be km/kg
So two sets of units are consistent if they refer to the set of same base units.

Hmm for example the given is:
newtons per centimeter , what will be the consistent unit?

Oh, I understand now. Well, except for the typo in the sentence that says "if you are using meter for length, you should use gram for mass." That is incorrect. As the rest of the paragraph states, the typical unit systems are:

MKS (SI) -- meter, kilogram, second

cgs -- centimeter, gram, second

There are similar consistent unit systems for goofy units like we use here in the US (pounds, whatever). This is a pretty good intro to units, with pointers out to other articles: